Prove that energy stored in a parallel plate capacitor is 1/2 c.v.. Form the graph between current (l) and voltage (V) as shown in the figure, identify the portion corresponding to negative resistance. 1 10. SSL and SO are two parallel concentric spheres enclosing charges Q and Q respectively as shown in fig. Q 2 IQ SSL SO (a) (b) 11. 12. What is the ratio of the electric flux through SSL and SO ?

How will the electric flux through the sphere SSL change, if a medium of dielectric constant 5 is introduced in he space inside SSL is place of air ? 1+1=2 1+2=2 Give any two limitation of Ohm’s Law. A and B are two points on a circular ring made of uniform wire of resistance R. If the part ABA of the ring subtends an angle B at the centre C of the ring as shown in fig. Prove that the effective resistance between A and B is 2 (2 – B ) B Reef= R 4112 C r A 13. 14. 15. Derive microscopic form of Ohm’s law. 22 Define the terms magnetic dip and magnetic declination. 17. 18. Arrange the given E. M. Additions in the descending order of their frequencies : Infra-red, X-rays, Ultra-violet and gamma rays OR Identify the part of ME spectrum, which is (I) Suitable for radar system used in aircraft navigation. (it) Adjacent to the low frequency end of the ME spectrum. (iii) Produced in nuclear reaction. (v) Produced by bombarding a metal target by high speed electrons. 2 The magnetic flux through a coil perpendicular to its plane is varying according to the relation cup = (4th + 5th + 8th + 5 ) Weber Calculate the induced current through the coil at t = 2 second, if the resistance of the coil. 6. Show that Lens’s law is in accordance with law of conservation of energy. The two resistors 400 Q and 800 Q are connected in series with 6 volt battery. It is sired to measure the current in the circuit. An ammeter of 10 Q resistance is used for this purpose. What will be the reading in the ammeter ‘similarly, if a voltmeter of 10,000 Q resistance is used to measure the potential difference across the 400 Q resistor what will be the reading in voltmeter ? 2 2 2 h+h+h+h=2 19. Define electric dipole moment.

Calculate electric field intensity at a point on the equatorial line off dipole. 3 20. Two point charges +1 OPAC and – Biopic are separated by a distance of 40 CM in air (I) Calculate the electrostatic potential energy of the system, assuming the zero of the potential energy to be at infinity. It) Draw an equipotent surface of the system. (iii) How much work is required to separate the two charges infinitely away from each other ? 1+1+1=3 Explain how will you use a potentiometer to (I) measure the internal resistance of a cell and (it) to compare the e. . F. Of two cells. 21. La+eh=3 In the circuit shown in the fig. EH = 2 volt, El = EYE = 6 volt, C = APP, RI = ERR RE- ERR = 40. Find the current in RE and energy stored in capacitor. La+eh=3 RI El c 26. 27. Prove that electromagnetic wave are transverse in nature. (Mathematically).